<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Feed_Writer
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Writer.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @category   Zend
 * @package    Zend_Feed_Writer
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Feed_Writer {
	/**
	 * Namespace constants
	 */
	const NAMESPACE_ATOM_03 = 'http://purl.org/atom/ns#';
	const NAMESPACE_ATOM_10 = 'http://www.w3.org/2005/Atom';
	const NAMESPACE_RDF = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#';
	const NAMESPACE_RSS_090 = 'http://my.netscape.com/rdf/simple/0.9/';
	const NAMESPACE_RSS_10 = 'http://purl.org/rss/1.0/';
	
	/**
	 * Feed type constants
	 */
	const TYPE_ANY = 'any';
	const TYPE_ATOM_03 = 'atom-03';
	const TYPE_ATOM_10 = 'atom-10';
	const TYPE_ATOM_ANY = 'atom';
	const TYPE_RSS_090 = 'rss-090';
	const TYPE_RSS_091 = 'rss-091';
	const TYPE_RSS_091_NETSCAPE = 'rss-091n';
	const TYPE_RSS_091_USERLAND = 'rss-091u';
	const TYPE_RSS_092 = 'rss-092';
	const TYPE_RSS_093 = 'rss-093';
	const TYPE_RSS_094 = 'rss-094';
	const TYPE_RSS_10 = 'rss-10';
	const TYPE_RSS_20 = 'rss-20';
	const TYPE_RSS_ANY = 'rss';
	
	/**
	 * PluginLoader instance used by component
	 *
	 * @var Zend_Loader_PluginLoader_Interface
	 */
	protected static $_pluginLoader = null;
	
	/**
	 * Path on which to search for Extension classes
	 *
	 * @var array
	 */
	protected static $_prefixPaths = array ();
	
	/**
	 * Array of registered extensions by class postfix (after the base class
	 * name) across four categories - data containers and renderers for entry
	 * and feed levels.
	 *
	 * @var array
	 */
	protected static $_extensions = array ('entry' => array (), 'feed' => array (), 'entryRenderer' => array (), 'feedRenderer' => array () );
	
	/**
	 * Set plugin loader for use with Extensions
	 *
	 * @param  Zend_Loader_PluginLoader_Interface
	 */
	public static function setPluginLoader(Zend_Loader_PluginLoader_Interface $loader) {
		self::$_pluginLoader = $loader;
	}
	
	/**
	 * Get plugin loader for use with Extensions
	 *
	 * @return  Zend_Loader_PluginLoader_Interface
	 */
	public static function getPluginLoader() {
		if (! isset ( self::$_pluginLoader )) {
			require_once 'Zend/Loader/PluginLoader.php';
			self::$_pluginLoader = new Zend_Loader_PluginLoader ( array ('Zend_Feed_Writer_Extension_' => 'Zend/Feed/Writer/Extension/' ) );
		}
		return self::$_pluginLoader;
	}
	
	/**
	 * Add prefix path for loading Extensions
	 *
	 * @param  string $prefix
	 * @param  string $path
	 * @return void
	 */
	public static function addPrefixPath($prefix, $path) {
		$prefix = rtrim ( $prefix, '_' );
		$path = rtrim ( $path, DIRECTORY_SEPARATOR );
		self::getPluginLoader ()->addPrefixPath ( $prefix, $path );
	}
	
	/**
	 * Add multiple Extension prefix paths at once
	 *
	 * @param  array $spec
	 * @return void
	 */
	public static function addPrefixPaths(array $spec) {
		if (isset ( $spec ['prefix'] ) && isset ( $spec ['path'] )) {
			self::addPrefixPath ( $spec ['prefix'], $spec ['path'] );
		}
		foreach ( $spec as $prefixPath ) {
			if (isset ( $prefixPath ['prefix'] ) && isset ( $prefixPath ['path'] )) {
				self::addPrefixPath ( $prefixPath ['prefix'], $prefixPath ['path'] );
			}
		}
	}
	
	/**
	 * Register an Extension by name
	 *
	 * @param  string $name
	 * @return void
	 * @throws Zend_Feed_Exception if unable to resolve Extension class
	 */
	public static function registerExtension($name) {
		$feedName = $name . '_Feed';
		$entryName = $name . '_Entry';
		$feedRendererName = $name . '_Renderer_Feed';
		$entryRendererName = $name . '_Renderer_Entry';
		if (self::isRegistered ( $name )) {
			if (self::getPluginLoader ()->isLoaded ( $feedName ) || self::getPluginLoader ()->isLoaded ( $entryName ) || self::getPluginLoader ()->isLoaded ( $feedRendererName ) || self::getPluginLoader ()->isLoaded ( $entryRendererName )) {
				return;
			}
		}
		try {
			self::getPluginLoader ()->load ( $feedName );
			self::$_extensions ['feed'] [] = $feedName;
		} catch ( Zend_Loader_PluginLoader_Exception $e ) {
		}
		try {
			self::getPluginLoader ()->load ( $entryName );
			self::$_extensions ['entry'] [] = $entryName;
		} catch ( Zend_Loader_PluginLoader_Exception $e ) {
		}
		try {
			self::getPluginLoader ()->load ( $feedRendererName );
			self::$_extensions ['feedRenderer'] [] = $feedRendererName;
		} catch ( Zend_Loader_PluginLoader_Exception $e ) {
		}
		try {
			self::getPluginLoader ()->load ( $entryRendererName );
			self::$_extensions ['entryRenderer'] [] = $entryRendererName;
		} catch ( Zend_Loader_PluginLoader_Exception $e ) {
		}
		if (! self::getPluginLoader ()->isLoaded ( $feedName ) && ! self::getPluginLoader ()->isLoaded ( $entryName ) && ! self::getPluginLoader ()->isLoaded ( $feedRendererName ) && ! self::getPluginLoader ()->isLoaded ( $entryRendererName )) {
			require_once 'Zend/Feed/Exception.php';
			throw new Zend_Feed_Exception ( 'Could not load extension: ' . $name . 'using Plugin Loader. Check prefix paths are configured and extension exists.' );
		}
	}
	
	/**
	 * Is a given named Extension registered?
	 *
	 * @param  string $extensionName
	 * @return boolean
	 */
	public static function isRegistered($extensionName) {
		$feedName = $extensionName . '_Feed';
		$entryName = $extensionName . '_Entry';
		$feedRendererName = $extensionName . '_Renderer_Feed';
		$entryRendererName = $extensionName . '_Renderer_Entry';
		if (in_array ( $feedName, self::$_extensions ['feed'] ) || in_array ( $entryName, self::$_extensions ['entry'] ) || in_array ( $feedRendererName, self::$_extensions ['feedRenderer'] ) || in_array ( $entryRendererName, self::$_extensions ['entryRenderer'] )) {
			return true;
		}
		return false;
	}
	
	/**
	 * Get a list of extensions
	 *
	 * @return array
	 */
	public static function getExtensions() {
		return self::$_extensions;
	}
	
	/**
	 * Reset class state to defaults
	 *
	 * @return void
	 */
	public static function reset() {
		self::$_pluginLoader = null;
		self::$_prefixPaths = array ();
		self::$_extensions = array ('entry' => array (), 'feed' => array (), 'entryRenderer' => array (), 'feedRenderer' => array () );
	}
	
	/**
	 * Register core (default) extensions
	 *
	 * @return void
	 */
	public static function registerCoreExtensions() {
		self::registerExtension ( 'DublinCore' );
		self::registerExtension ( 'Content' );
		self::registerExtension ( 'Atom' );
		self::registerExtension ( 'Slash' );
		self::registerExtension ( 'WellFormedWeb' );
		self::registerExtension ( 'Threading' );
		self::registerExtension ( 'ITunes' );
	}
	
	public static function lcfirst($str) {
		$str [0] = strtolower ( $str [0] );
		return $str;
	}

}
